[WorldWind学习]20.修改ShapeFileLayer类及托管D3D文字绘制方法

PluginSDKShapeFileLayer.cs Line:1027
char[] fieldDataChars = dbfReader.ReadChars(fieldHeaders[j].FieldLength);
string fieldData = new string( fieldDataChars );
为
byte[] fieldDataChars = dbfReader.ReadBytes(fieldHeaders[j].FieldLength);
string fieldData = System.Text.Encoding.Default.GetString( fieldDataChars );

 

if(m_LabelList.Count > 0)
{
    System.Drawing.Color iconColor = System.Drawing.Color.FromArgb(m_IconOpacity, 255, 255, 255);
    foreach(Shapefile_Point p in m_LabelList)
    {
        Vector3 cartesianPoint = MathEngine.SphericalToCartesian(p.Y, p.X, drawArgs.WorldCamera.WorldRadius + drawArgs.WorldCamera.TerrainElevation);
        if(!drawArgs.WorldCamera.ViewFrustum.ContainsPoint(cartesianPoint) ||MathEngine.SphericalDistanceDegrees(p.Y, p.X, drawArgs.WorldCamera.Latitude.Degrees, drawArgs.WorldCamera.Longitude.Degrees) > 90.0)
        continue;
        Vector3 projectedPoint = drawArgs.WorldCamera.Project(cartesianPoint - referenceCenter);
        
        m_Sprite.Begin(SpriteFlags.AlphaBlend);
        if(m_IconTexture != null)
        {
            float xscale = (float)m_IconWidth / m_IconTextureDescription.Width;
            float yscale = (float)m_IconHeight / m_IconTextureDescription.Height;
            m_Sprite.Transform = Matrix.Scaling(xscale,yscale,0);
            m_Sprite.Transform *= Matrix.Translation(projectedPoint.X, projectedPoint.Y, 0);
            m_Sprite.Draw( m_IconTexture,
                new Vector3( m_IconWidth>>1, m_IconHeight>>1,0),
                Vector3.Empty,
                iconColor.ToArgb() );

            // Reset transform to prepare for text rendering later
            m_Sprite.Transform = Matrix.Identity;
        }

        if(m_ShapeTileArgs.ShowLabels && m_ShapeTileArgs.DataKey != null)
        {    
            // Render label
            if(p.Tag != null)
            {
                // Render name field
                const int labelWidth = 1000; // Dummy value needed for centering the text
                if(m_IconTexture==null)
                {
                    // Center over target as we have no bitmap
                    Rectangle rect = new Rectangle(
                        (int)projectedPoint.X - (labelWidth>>1), 
                        (int)(projectedPoint.Y - (drawArgs.defaultDrawingFont.Description.Height >> 1)),
                        labelWidth, 
                        drawArgs.screenHeight );

                    drawArgs.defaultDrawingFont.DrawText(m_Sprite, p.Tag.ToString(), rect, DrawTextFormat.Center, m_ShapeTileArgs.LabelColor);
                }
                else
                {
                    // Adjust text to make room for icon
                    int spacing = (int)(m_IconWidth * 0.3f);
                    if(spacing>10)
                        spacing = 10;
                    int offsetForIcon = (m_IconWidth>>1) + spacing;

                    Rectangle rect = new Rectangle(
                        (int)projectedPoint.X + offsetForIcon, 
                        (int)(projectedPoint.Y - (drawArgs.defaultDrawingFont.Description.Height >> 1)),
                        labelWidth, 
                        drawArgs.screenHeight );

                    drawArgs.defaultDrawingFont.DrawText(m_Sprite, p.Tag.ToString(), rect, DrawTextFormat.WordBreak, m_ShapeTileArgs.LabelColor);
                }
            }
        }        
        m_Sprite.End();
    }
}

有一个文字3D世界坐标点投影到屏幕的过程，在屏幕绘制。